Although a big WiMAX deal brought some good news to Sprint Nextel last week, the beleaguered wireless provider sounded a less happy note today, reporting the loss of about one million additional subscribers last quarter, along with a $505 million drop in revenue.

The number of subscribers for Sprint's current 3G services fell to 52.8 million for the first quarter of 2008, down from 53.6 million during the same period a year ago.

In contrast, AT&T and Verizon Wireless each recently announced quarterly gains in wireless customers, implying that Sprint is losing market share in its current 3G business to those two rivals.

Last week's announcement of a WiMAX spinoff by Sprint and Clearwire -- funded by $3.2 billion in investments from Google, Intel Capital, Comcast, Time Warner, and Bright House Networks -- raised the possibility that Sprint might leapfrog over AT&T and Verizon in the future 4G space.

The WiMax deal also calls for some new commercial relationships around 3G wireless that look likely to give Sprint a revenue boost.

But for the current quarter, at least, Sprint is forecasting only modest improvements to its financial picture.

During the first quarter, Sprint launched a new marketing campaign, along with a $99.99 per month unlimited calling and data plan, which brings pricing for current wireless services below those of AT&T and Verizon.

In a conference call with analysts, Sprint CEO Dan Hesse suggested that Sprint is still considering some sort of sale or spinoff of its acquired Nextel business, which has given rise to many of the subscriber losses due to technical problems with Nextel's iDEN network.

At the VON.x conference at the end of March, Sprint talked in the direction of building an IP-based "Unified Service Architecture" to serve as the basis for iDEN, WiMAX, and Spring's long-time CDMA network.

Sprint is still "committed to" former Nextel subscribers in its current customer base, Hesse said today. But "nothing is off the table completely," according to the Sprint CEO.